<?phpheader("Content-Type:text/html;charset=utf-8");/** *php操作mysql的工具類 */class Db{  private $_db = null;//數據庫連接句柄  private $_table = null;//表名  private $_where = null;//where條件  private $_order = null;//order排序  private $_limit = null;//limit限定查詢  private $_group = null;//group分組  private $_configs = array(        'hostname' => 'localhost',        'dbname'  => 'test',        'username' => 'root',        'password' => '1234'      );//數據庫配置  /**   * 構造函數，連接數據庫   */  public function __construct(){    $link = $this->_db;    if(!$link){      $db = mysqli_connect($this->_configs['hostname'],$this->_configs['username'],$this->_configs['password'],$this->_configs['dbname']);      mysqli_query($db,"set names utf8");      if(!$db){        $this->ShowException("錯誤信息".mysqli_connect_error());      }      $this->_db = $db;    }  }  /**   * 獲取所有數據   *   * @param   <type>  $table The table   *   * @return   boolean All.   */  public function getAll($table=null){    $link = $this->_db;    if(!$link)return false;    $sql = "SELECT * FROM {$table}";    $data = mysqli_fetch_all($this->execute($sql));    return $data;  }  public function table($table){    $this->_table = $table;    return $this;  }  /**   * 實現查詢操作   *   * @param   string  $fields The fields   *   * @return   boolean ( description_of_the_return_value )   */  public function select($fields="*"){    $fieldsStr = '';    $link = $this->_db;    if(!$link)return false;    if(is_array($fields)){      $fieldsStr = implode(',', $fields);    }elseif(is_string($fields)&&!empty($fields)){      $fieldsStr = $fields;    }    $sql = "SELECT {$fields} FROM {$this->_table} {$this->_where} {$this->_order} {$this->_limit}";    $data = mysqli_fetch_all($this->execute($sql));    return $data;  }  /**   * order排序   *   * @param   string  $order The order   *   * @return   boolean ( description_of_the_return_value )   */  public function order($order=''){    $orderStr = '';    $link = $this->_db;    if(!$link)return false;    if(is_string($order)&&!empty($order)){      $orderStr = "ORDER BY ".$order;    }    $this->_order = $orderStr;    return $this;  }  /**   * where條件   *   * @param   string $where The where   *   * @return   <type> ( description_of_the_return_value )   */  public function where($where=''){    $whereStr = '';    $link = $this->_db;    if(!$link)return $link;    if(is_array($where)){      foreach ($where as $key => $value) {        if($value == end($where)){          $whereStr .= "`".$key."` = '".$value."'";        }else{          $whereStr .= "`".$key."` = '".$value."' AND ";        }      }      $whereStr = "WHERE ".$whereStr;    }elseif(is_string($where)&&!empty($where)){      $whereStr = "WHERE ".$where;    }    $this->_where = $whereStr;    return $this;  }  /**   * group分組   *   * @param   string  $group The group   *   * @return   boolean ( description_of_the_return_value )   */  public function group($group=''){    $groupStr = '';    $link = $this->_db;    if(!$link)return false;    if(is_array($group)){      $groupStr = "GROUP BY ".implode(',',$group);    }elseif(is_string($group)&&!empty($group)){      $groupStr = "GROUP BY ".$group;    }    $this->_group = $groupStr;    return $this;  }  /**   * limit限定查詢   *   * @param   string $limit The limit   *   * @return   <type> ( description_of_the_return_value )   */  public function limit($limit=''){    $limitStr = '';    $link = $this->_db;    if(!$link)return $link;    if(is_string($limit)||!empty($limit)){      $limitStr = "LIMIT ".$limit;    }elseif(is_numeric($limit)){      $limitStr = "LIMIT ".$limit;    }    $this->_limit = $limitStr;    return $this;  }  /**   * 執行sql語句   *   * @param   <type>  $sql  The sql   *   * @return   boolean ( description_of_the_return_value )   */  public function execute($sql=null){    $link = $this->_db;    if(!$link)return false;    $res = mysqli_query($this->_db,$sql);    if(!$res){      $errors = mysqli_error_list($this->_db);      $this->ShowException("報錯啦！<br/>錯誤號：".$errors[0]['errno']."<br/>SQL錯誤狀態：".$errors[0]['sqlstate']."<br/>錯誤信息：".$errors[0]['error']);      die();    }    return $res;  }  /**   * 插入數據   *   * @param   <type>  $data  The data   *   * @return   boolean ( description_of_the_return_value )   */  public function insert($data){    $link = $this->_db;    if(!$link)return false;    if(is_array($data)){      $keys = '';      $values = '';      foreach ($data as $key => $value) {        $keys .= "`".$key."`,";        $values .= "'".$value."',";      }      $keys = rtrim($keys,',');      $values = rtrim($values,',');    }    $sql = "INSERT INTO `{$this->_table}`({$keys}) VALUES({$values})";    mysqli_query($this->_db,$sql);    $insertId = mysqli_insert_id($this->_db);    return $insertId;  }  /**   * 更新數據   *   * @param   <type> $data  The data   *   * @return   <type> ( description_of_the_return_value )   */  public function update($data){    $link = $this->_db;    if(!$link)return $link;    if(is_array($data)){      $dataStr = '';      foreach ($data as $key => $value) {        $dataStr .= "`".$key."`='".$value."',";      }      $dataStr = rtrim($dataStr,',');    }    $sql = "UPDATE `{$this->_table}` SET {$dataStr} {$this->_where} {$this->_order} {$this->_limit}";    $res = $this->execute($sql);    return $res;  }  /**   * 刪除數據   *   * @return   <type> ( description_of_the_return_value )   */  public function delete(){    $link = $this->_db;    if(!$link)return $link;    $sql = "DELETE FROM `{$this->_table}` {$this->_where}";    $res = $this->execute($sql);    return $res;  }  /**   * 異常信息輸出   *   * @param   <type> $var  The variable   */  private function ShowException($var){    if(is_bool($var)){      var_dump($var);    }else if(is_null($var)){      var_dump(NULL);    }else{      echo "<pre style='position:relative;z-index:1000;padding:10px;border-radius:5px;background:#F5F5F5;border:1px solid #aaa;font-size:14px;line-height:18px;opacity:0.9;'>".print_r($var,true)."</pre>";    }  }}$db = new Db();//查詢操作var_dump($db->table('user')->where('id > 2')->order('id desc')->limit('2,4')->select());//插入操作var_dump($db->table('user')->insert(array('username'=>'user','password'=>'pwd')));//更新操作var_dump($db->table('user')->where('id = 1')->update(array('username'=>'user1','password'=>'pwd1')));//刪除操作var_dump($db->table('user')->where('id = 1')->delete());